Solution 2.9.5.5
Applying the Laplace transform yields
s
2
Y (s);sy(0);y
[1]
(0)+ 4[sY (s);y(0)];3Y (s)=0:
Rearranging yields
(s
2
+4s;3)Y (s)=sy(0)+ 4y(0)+ y
[1]
(0);;
or
Y (s)=
sy(0)+ 4y(0)+ y
[1]
(0)
[s +(2;
p
7)][s +(2+
p
7)
For the given initial conditions we then have
Y (s) =
8(s +4)
[s +(2;
p
7)][s+(2+
p
7)]
=
A
s +(2;
p
7)
+
B
s +(2+
p
7)
:
A = [s +(2;
p
7)]Y (s)
s=;2+
p
7
=
"
8(s +4)
[s +(2+
p
7)]
#
s=;2+
p
7
= 7:0237
B = [s +(2+
p
7)]Y (s)
s=;2;
p
7
=
"
8(s +4)
[s +(2;
p
7)]
#
s=;2;
p
7
= 0:9763
y(t) = [7:0237e
(;2+
p
7)t
;0:9762e
(;2;
p
7)t
]1(t)
= [7:0237e
0:6458t
;0:9762e
;4:6458t
]1(t)
1